Automatic actuators for carburetor choke valves of the type having a heating panel which heats a bimetal mechanically associated with the choke valve of a carburetor for automatically adjusting the position of the choke valve by thermal strain of the bimetal are commonly used on internal combustion engines. These devices normally have a temperature sensor encased along with the heating panel and bimetal in a housing, said temperature sensor sensing the temperature of the bimetal and regulating the current to the heating panel so as to attempt to maintain the temperature of the bimetal beneath a certain temperature for prevention of excessive thermal deformation of the bimetal.
However, with devices of conventional structure, there are disadvantages in that the temperature sensor only receives radiant heat from the heating panel resulting in delayed sensing of the bimetal temperature, which can cause the bimetal and other parts of the actuator to overheat and suffer thermal damage.